Neoplastic disease which includes cancer is one of the leading causes of death among human beings. There are over 1.3 million new cases of cancer diagnosed in the United States each year and 550,000 deaths. Detecting cancer early, before it has spread to secondary sites in the body, greatly increases a host's chances of survival. However, early detection of cancer is not always possible, and even when it is, treatments are unsatisfactory, especially in cases of highly malignant cancers. Cancer treatments, including chemotherapy and radiation, are much less effective in later stages, especially when neoplastic growths are large and/or constitute a high tumor burden. (See Hillard Stanley, Cancer Treat. Reports, Vol. 61, No. 1, Jan/Feb 1977, p. 29-36, Tannock, Cancer Research, 42, 4921-4926, Dec. 1982).
Tumor regression associated with exposure to various viruses has been reported. Most of the viruses described are pathogenic in humans, and include mumps and measles. The effect of other specific viruses on particular types of cancer cells has also been described. Smith et al, (1956) Cancer, 9, 1211 (effect of adenovirus on cervix carcinoma); Holzaepfel et al, (1957) Cancer, 10, 557 (effect of adenovirus on epithelial tumor); Taylor et al, (1970) J. Natl. Cancer Inst., 44, 515 (effect of bovine enterovirus-1 on sarcoma-1); Shingu et al, (1991) J. General Virology, 72, 2031 (effect of bovine enterovirus MZ-468 on F-647, a leukemia cells); Suskind et al, (1957) PSEBM, 94, 309 (effect of coxsackie B3 virus on HeLa tumor cells); Rukavishnikova et al, (1976) Acta Virol., 20, 387 (effect of influenza A strain on ascites tumor).
The earliest references described partial tumor regression in patients treated with live attenuated viral vaccine with the aim to vaccinate them against smallpox or rabies. See DePace, N. G. (1912) Ginecologia, 9, 82-88; Salmon, P. & Baix (1922) Compt. Rend. Soc. Biol., 86, 819-820. Partial regression of tumors and regression of leukemias have also been noted during naturally occurring measles infections. See Pasquinucci, G. (1971) Lancet, 1, 136; Gross, S. (1971) Lancet, 1, 397-398; Bluming, A. Z. and Ziegler, J. L. (1971) Lancet, 2, 105-106. In one study of 90 cancer patients intentionally infected with live mumps virus, partial tumor regression was noted in 79 cases. See Asada (1994) Cancer, 34, 1907-1928. While the side effects of these viruses were temporary, serious sequela of infection with these human pathogens is of major concern.
Viruses are categorized as follows [see Murphy A. and Kingsbury D W, 1990, In: Virology, 2nd Edition (Ed. Fields, B. N.), Raven Press, New York, pp 9-35]:
Dividing CharacteristicsVirus Family NamesRNA virusesssa RNA, positive-sense,Picornaviridae, Calciviridaenonsegmented,nonenveloped,ssRNA, positive-sense,Togaviridae, Flaviviridae,nonsegmented,Coronaviridaeenveloped,ssRNA, negative-sense,Rhabdoviridae, Filoviridae,nonsegmented,Paramyxoviridaeenveloped,ssRNA, negative-sense,Orthomyxoviridaesegmented, envelopedssRNA, ambisense,Bunyaviridae, Arenaviridaesegmented, envelopedds bRNA, positive-senseReoviridae, Birnaviridaesegmented,nonenvelopedssRNA, DNA step inRetroviridaereplication, positive-sense, nonsegmented,envelopedDNA virusesss/dsDNA, nonenvelopedHepadnaviridaessDNA, nonenvelopedParvoviridaedsDNA, nonenvelopedPapovaviridae, AdenoviridaedsDNA, envelopedHerpesviridae, Poxviridae,Iridoviridaeass = single strandedbds = double-stranded
Included among the family Herpesviridae (or Herpesviruses), are the subfamilies Alphaherpesvirus (including Genus Varicellarviurs and Genus Simpexvirus), Betaherpesvirus, and Gammaherpesvirus.
Newcastle disease virus (“NDV”) is a member of the Paramyxoviridae (or Paramyxoviruses). The natural hosts for NDV are chickens and other birds. NDV typically binds to certain molecules on the surface of animal host cells, fuses with the cell surface, and injects its genetic material into the host. NDV is a cytocidal virus. Once inside the cell, the viral genes direct the host cell to make copies of the virus leading to death of the host cell, releasing the copies of NDV which infect other cells. Unlike some viruses, NDV is not known to cause any serious human disease. Unlike other kinds of viruses (e.g., HTLV-1, Hepatitis B). Paramyxoviruses are not known to be carcinogenic. Temporary regression of tumors has been reported in a small number of patients exposed to NDV, See, Csatary, L. K. (1971) Lancet, 2, 825. Csatary noted the regression of a gastrointestinal cancer in a chicken farmer during an epidemic of Newcastle disease in his chickens. In a similar anecdotal report, Cassel, W. A. and Garrett, R. E. (1965) Cancer, 18, 863-868, noted regression of primary cervical cancer, which had spread to the lymph nodes, in a patient following injection of NDV into the cervical tumor. Since the mechanism of tumoricidal activity was thought to be immunologic, no work was carried out to address direct tumor cytotoxicity of the virus. Instead, efforts focused upon the immuno-modulating effects of NDV. See, for example, Murray, D. R., Cassel, W. A., Torbin, A. H., Olkowski, Z. L., & Moore, M. E. (1977) Cancer, 40, 680; Cassel, W. A., Murray, D. R., & Phillips, H. S. (1983) Cancer, 52, 856; Bohle, W., Schlag, P. J., Liebrich, W., Hohenberger, P., Manasterski, M., Miller, P., and Schirrmacher, V. (1990) Cancer, 66, 1517-1523.
The selection of a specific virus for tumor regression was based on serendipity or trail and error in the above citations. Only recently, have rational, mechanism-based applications for virus use in cancer treatment been developed using DNA viruses. Examples of this type of approach are found in the development of recombinant adenoviral vectors that replicate only in tumors of specific tissue origin (Rodriguez, R. et al, 1997 Cancer Res., 57:2559-2563), or those that lack certain key regulatory proteins (Bischoff, J R, et al, 1996 Science, 274:373-376). Another recent approach has been the use of a replication-incompetent recombinant adenoviral vector to restore a critical protein function lost in some tumor cells (Zhang, W W, et al, 1994 Cancer gene therapy, 1:5-13). Finally, herpes simplex virus has also been engineered to replicate preferentially in the rapidly dividing cells that characterize tumors (Mineta, T., et al, 1994 Cancer Res., 54:3963-3966).
U.S. application Ser. No. 08/260,536, hereby incorporated by reference in its entirety, discloses the use of NDV or other Paramyxovirus in the treatment of cancer.
Viral IFN transgene expression
One common approach to the treatment of cancer with viral therapeutics has been the use of virus vectors for the delivery of certain genes to the tumor mass.
Recombinant adenovirus, adeno-associated virus, vaccinia virus and retroviruses have all been modified to express an interferon gene alone or in combination with other cytokine genes.
In Zhang et al. ((1996) Proc. Natl. Acad. Sci., USA 93:4513-4518), a recombinant adenovirus expressing a human interferon consensus (i.e., synthetic) gene was used to treat human breast cancer (and other) xenografts in nude mice. The authors concluded “. . . a combination of viral oncolysis with a virus of low pathogenicity, itself resistant to the effects of IFN and IFN gene therapy, might be a fruitful approach to the treatment of a variety of different tumors, in particular breast cancer.” In contrast to subject invention which relates to interferon-sensitive viruses, Zhang et al. (1996) teach the use of an interferon-resistant adenovirus in the treatment of tumors.
In Zhang et. al. ((1996) Cancer Gene Ther., 3:31-38), adeno-associated virus (AAV) expressing consensus IFN was used to transduced human tumor cells in vitro followed by injection into nude mice. The transduced tumors either did not form tumors or grew slower than the non-transduced controls. Also, injection of one transduced human tumor cell into the tumor mass of another, non-transduced tumor resulted in a small decrease in size. In Peplinski et al. ((1996) Ann. Surg. Oncol., 3:15-23), IFN gamma (and other cytokines, expressed either alone, or in combination) were tested in a mouse breast cancer model. Mice were immunized with tumor cells virally modified with recombinant vaccinia virus. When re-challenged with tumor cells, the mice immunized with virally modified cells has statistical improvement in the disease-free survival time.
Gastl, et al. ((1992) Cancer Res., 52:6229-6236), used IFN gamma-expressing retroviral vectors to transduce renal carcinoma cells in vitro. These cells were shown to produce higher amounts of a number of proteins important for the function of the immune system.
Restifo et al. ((1992) J. Exp. Med., 175:1423-1431), used IFN gamma-expressing retroviral vector to transduce a murine sarcoma cell line allowing the tumor cell line to more efficiently present viral antigens to CD8+ T cells. Howard, et al. ((1994) Ann. NY Acad. Sci., 716:167-187), used IFN gamma-expressing retroviral vector to transduce murine and human melanoma tumor cells. These cells were observed to increase the expression of proteins important to immune function. These cells were also less tumorigenic in mice as compared to the non-transduced parent line, and resulted in activation of a tumor-specific CTL response in vivo.
Use of Therapeutic Doses of Interferon as an Adjuvant to Viral Cancer Therapy
Because of the known immune-enhancing properties of IFN, several studies have examined the use of IFN protein in combination with other viral cancer vaccine therapies.
In Kirchner et al. ((1995) World J. Urol., 13:171-173), 208 patients were immunized with autologous, NDV-modified, and lethally irradiated renal-cell carcinoma tumor cells, and were co-treated with low dose IL-2 or IFN alpha. The authors stated that this treatment regime results in an improvement over the natural course in patients with locally-advanced renal-cell carcinoma. The dose was approximately 3.3×103 to 2.2×105 PFU/kg. This was a local therapy, as opposed to a systemic approach, with the goal of inducing an anti-tumor immune response.
Tanaka et al. ((1994) J. Immunother. Emphasis Tumor Immunol., 16:283-293), co-administered IFN alpha with a recombinant vaccinia virus as a cancer vaccine therapy model in mice. This study showed a statistical improvement in survivability in mice receiving IFN as compared to those that did not. The authors attributed efficacy of IFN to the induction of CD8-positive T cells in those animals.
Arroyo et al. ((1990) Cancer Immunol. Immunother., 31:305-311) used a mouse model of colon cancer to test the effect of IFN alpha and/or IL-2 co-therapy on the efficacy of a vaccinia virus colon oncolysate (VCO) cancer treatment. They found that the triple treatment of VCO+IL-2+IFN was most efficacious in this murine model. This approach relies on immunization as the mechanism of anti-tumor activity.
IFN was used in these studies to augment the ability of the cancer cells to be recognized by the immune system.